It has been well-known to the skilled in the art that injection molded scrap of thermoplastic material can be reclaimed and recycled and that such an apparatus consisting of integrally combined grinding device and a blending device has been developed, because thermoplastic material can easily be remelted and remolded.
Thermosetting material, however, cannot be remelted nor remolded; therefore, thermosetting scrap has been ground and used at best as a filler for virgin material, or as adding material to reduce the resin content of the compound, and has not been positively reused.
Accumulation of unreclaimed thermosetting scrap has been a headache or a serious waste problem for thermosetting material molders on the one hand, but recent research has proved, on the other hand, that pulverized and atomized thermosetting scrap can be effectively used by blending with virgin material up to about 50 percent, without much impairing flexial strength, impact strength and shrinkage properties, etc. of moldings of such scrap blended material.
Under these circumstances, there has been developed, as reported in the Nov. 1974 issue of the magazine "Modern Plastics International" (p. 66), an apparatus of an integral unit for grinding thermosetting scrap and blending the ground and pulverized material with virgin material at a desired ratio. The present invention is an improvement of this apparatus.